The goal of the proposed project is to examine the predictive role of working memory (WM) networks in reduced alcohol consumption, among a group of HIV positive heavy drinkers, receiving a Motivational Interviewing (MI) intervention. Hazardous alcohol use (HAU) is common in people living with HIV (PLWH) with estimates of HAU between 5-33% in this population (4-7). There are many deleterious consequences of hazardous alcohol use in this population, which include increased risk of: HIV transmission, exacerbation of comorbid medical conditions, comorbid psychiatric diagnoses, and other psychosocial consequences. In order to effectively intervene upon alcohol use, it is important to understand the mechanisms by which cognitive abilities impact intervention effectiveness. Previous studies have suggested that WM abilities, prior to behavioral intervention, are associated with intervention outcome (11-12). The basic role of WM has been defined as a form of memory that supports the temporary storage and maintenance of internal representations and mediates the controlled manipulation of these representations (13-14). A critical component of WM is the phonological loop which supports the process of storing speech based information, so that it can be manipulated (13). A critical element of MI, which involves the use of phonological loop resources, is the element of client change talk. Client change talk is among the most consistent predictors of intervention success because verbalizing change talk can help to resolve ambivalence, which can help move the individual toward a greater likelihood of behavior change (15-16). MI is one of the most effective behavioral treatments for problems with alcohol. However, no studies have directly investigated the predictive role of WM networks, as predictors of drinking reduction following MI. We aim to examine WM networks using functional magnetic resonance imaging (fMRI) blood oxygen level dependent (BOLD) response during n-back (0-back and 2-back) tasks, resting state functional connectivity analyses, as well as WM abilities using cognitive measures, to evaluate whether baseline WM abilities are predictive of alcohol reduction, in response to MI intervention. We will test whether decreased fMRI BOLD activation in WM regions of interest (ROI) during n-back performance predict alcohol reduction among individuals receiving MI intervention. We will also evaluate whether higher baseline neurocognitive WM abilities (N-back performance, Letter Number Sequencing, Trails, Stroop) predict greater alcohol reduction in response to MI. Finally, we will determine if higher baseline Total Independence levels (i.e., functional connectivity) between WM ROIs predict reduced alcohol consumption at 6 months, among individuals receiving MI. Findings from this research will contribute to an understanding of mechanisms associated with successful response to behavioral intervention. Furthermore, understanding changes in the underlying neural networks associated with positive response to MI, may inform future interventions, which may focus on enhancing WM abilities, prior to behavioral alcohol reduction intervention.